From ea83e4141c4a4c09739b7c7ba731e83f2ec71764 Mon Sep 17 00:00:00 2001
From: xuxin <840198532@qq.com>
Date: Sat, 17 Jan 2026 10:24:24 +0800
Subject: [PATCH] =?UTF-8?q?day05-=E6=95=B0=E7=BB=84=E7=9A=84=E5=BC=82?=
 =?UTF-8?q?=E5=B8=B8=5F=E7=A9=BA=E6=8C=87=E9=92=88=E5=BC=82=E5=B8=B8?=
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---
 day05/src/com/inmind/array01/Demo04.java | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 day05/src/com/inmind/array01/Demo04.java

diff --git a/day05/src/com/inmind/array01/Demo04.java b/day05/src/com/inmind/array01/Demo04.java
new file mode 100644
index 0000000..777758f
--- /dev/null
+++ b/day05/src/com/inmind/array01/Demo04.java
@@ -0,0 +1,19 @@
+package com.inmind.array01;
+/*
+.数组的异常_空指针异常
+NullPointerException
+空指针异常
+ */
+public class Demo04 {
+    public static void main(String[] args) {
+        int[] arr = {1, 2, 3};//省略了new
+        System.out.println(arr[2]);//3
+
+        arr = null;//空常量，它的作用是给引用数据类型初始化的，也就是引用数据类型的默认值
+        if (arr != null) {//对引用数据类型增加安全性的判断
+            System.out.println(arr[2]);//如果对应的引用数据类型为null，还继续操作，就会报NullPointerException
+        }
+
+        System.out.println("程序结束");
+    }
+}